The Effects of Light and Moisture on Two Species From Contiguous Communities of South-Facing Bluffs in Interior Alaska, USA
Wesser SD. 1991. The Effects of Light and Moisture on Two Species From Contiguous Communities of South-Facing Bluffs in Interior Alaska, USA. Arctic and Alpine Research. 23(1):99-103
Steep, south-facing bluffs in interior Alaska support both deciduous forest and steppe vegetation. Most species show a range in community fidelity; however, others are restricted in their distribution. A steppe endemic (Potentilla hookeriana) and a forest species (Pyrola secunda) were grown in a greenhouse factorial experiment to test the hypothesiss that light and soil moisture are important controls over plant performance and distribution on south-facing bluffs. Survival of both species showed strong and opposite ligth effects. Under low light, Potentilla survival was 48% less than under high light levels. Pyrola survival was reduced 44% in high light. Pyrola survivors showed few significant growth responses to either factor. These results of the effects suggest that the distribution and abundance of these species may be primarily a result of the effects of light on survival. The steppe species showed a greater range in growth response than the forests species, which is consistent with the fact that Potentilla occupies a broader segment of the forest-steppe gradient than Pyrola.
- Type
- Journal Article
- Authors
- Wesser, S
- Units
- YUCH
- Keywords
- Bluffs, Flora, Plant Communities, Vegetation